Fluid filter assembly with concave surface in the closed end of the housing

ABSTRACT

A filter assembly includes a house open at one end and closed at the other end. An end plate is secured to the housing and closes the open end. An annular filter media/core assembly is disposed in the housing. The end plate has inlet openings and an outlet opening therein. A combination valve disposed between the end plate and the annular filter media/core assembly controls fluid flow through the inlet openings and the outlet opening. The closed end has a concave portion which is disposed in the opening in the annular filter media/core assembly. The concave portion in the housing helps reduce the overall height of the filter assembly, thus reducing the interior void volume of the filter assembly, which reduces the quantity of oil necessary to fill the system. The provision of a concave portion in the closed end of the housing helps to center the annular filter media/core assembly in the housing and improves the manufacturing and assembly processes.

RELATED APPLICATION

This application is a continuation-in-part of patent application Ser.No. 10/715,682 filed Nov. 18, 2003 and entitled Fluid Filter Assembly.

BACKGROUND OF THE INVENTION

A. Field of the Invention

This invention pertains to a fluid filter assembly having a combinationvalve retained between a filter media/core assembly and an end plateand, more particularly, to a fluid filter assembly having a novelunitary combination check valve and bypass valve cooperating with aunique end plate for controlling the flow of fluid into and out from thefluid filter assembly. Further, the invention pertains to a fluid filterassembly that includes a housing having a concave surface thatcooperates with the annular filter media/core assembly to eliminate thespring used in the prior pending application and to help center theannular filter media/core assembly in the housing.

B. Description of Related Art

There is known in the prior art a filter device having a housing with anopen end, a filter element received in the housing, an end plate closingthe open end and having inlet and outlet openings therein, and a valvefor cooperating with the inlet openings to allow oil to flow into thefilter through the inlet openings, but prevents flow of oil in a reversedirection. An example may be seen in Minowa et al. Pat. No. 6,595,372.Prior filters are known that include a combination valve having twoportions, the first portion for closing the inlet openings to block theflow of oil back out of the inlet openings when the oil is not beingcirculated and the second portion for opening a bypass opening when thefilter media is clogged for returning oil to the engine to keep theengine lubricated even though the filter element is clogged. An exampleof such construction is Covington Pat. No. 5,405,527.

The present invention improves upon the filter assembly with combinationvalve, shown for example, in the Covington Pat. No. 5,405,527 andovercomes disadvantages and deficiencies of such prior artconstructions.

C. SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved filterassembly that has a simpler design and fewer parts than prior art filterassemblies.

Another object of the present invention is to provide an improved filterassembly with a housing having a concave surface in the closed end thateliminates the spring of the prior co-pending application Ser. No.10/715,682 and helps to center the filter media/core assembly in thehousing.

Yet another object of the present invention is to provide an improvedfilter assembly having a housing with a concave surface in the closedend that engages the annular filter media/core assembly to help reducethe overall height of the filter assembly and to reduce the inner voidvolume of the filter assembly, thus requiring less oil to fill thesystem.

Another object of the present invention is to provide an improved filterassembly wherein manufacturing and assembly are improved such thatfixturing devices can be eliminated.

Other objects and advantages of the present invention will become moreapparent hereinafter.

The invention pertains to a filter assembly having a housing open at oneend and closed at the other end. The closed end has a concave portionthat is constructed and arranged to engage with and center an annularfilter media/core assembly disposed in the housing. The end plate has atleast two inlet openings and an outlet opening therein. A combinationvalve is disposed and retained between the filter media/core assemblyand the end plate. The combination valve has a first portion cooperatingwith the first inlet opening in the end plate and a second portioncooperating with the second inlet opening. In normal operation the firstportion of the combination valve will yield before the second portion ofthe combination valve and fluid flow will pass through the first inletopening, the filter element and then be discharged through the outletopening. When the filter element begins to clog, pressure upstream ofthe first portion will build and upon attainment of a predeterminedpressure, the second portion will open the second inlet opening andfluid flow can pass through the second inlet opening and out the outletopening, thereby bypassing the filter media/core assembly. A resilientseal on each end cap of the annular filter media/core assembly help biasthe filter element toward the end plate to retain the combination valvein place and to seal fluid flow from between the filter media and theconcave surface of the housing, from between the combination valve andthe filter media and from between the combination valve and the endplate.

D. BRIEF DESCRIPTION OF THE DRAWING

There is shown in the attached drawing a presently preferred embodimentof the present invention wherein like numerals refer to like elementsand wherein:

FIG. 1 is a side view of the filter assembly of the present invention,with part of the housing broken away to show interior parts includingthe combination check and bypass valve.

E. DETAILED DESCRIPTION OF THE INVENTION

There is shown in FIG. 1 a filter assembly embodying the presentinvention. The filter assembly 10 includes a generally cup-shapedcylindrical shell or housing 12 that is open at one end and closed atthe other. The closed end of the housing 12 has a central concaveportion or depression 13 formed therein. Disposed within the housing 10is a filter means 15 which comprises an annular filter element 14mounted on a core 16. The concave portion 13 is adapted to engage withinthe opening at the top of the annular filter element 14 to help preventfluid to be filtered from bypassing the filter element and to helpcenter the filter element 14 in the housing 12. Provided in the open endof the housing 10 is an end plate 18, which has a lid 20 securedthereto. An annular, resilient gasket 22 is received and retained in arecess in the lid 20 for providing a seal between the filter assembly 10and the engine block (not shown) to which the filter assembly 10 issecured in normal use.

The combination valve 26, which is retained between the lower end of thefilter element 14 and the top of the end plate 18 includes a firstportion 28 for controlling flow through the first inlet opening oropenings 30 and a second portion 32 for controlling flow through thesecond inlet opening or openings 34. The first portion 28 is moreresilient than the second portion 30 and will open under a lesserpressure, whereas the second portion 32 is stiffer and requires a higherpressure to open same. In a presently preferred embodiment of theinvention, the first portion 28 of the combination valve 26 will openthe first inlet openings at a minimum opening pressure, for example, onthe order of 1 psi and the second portion 32 will open the second inletopenings 34 at a predetermined higher pressure, for example on the orderof 8-10 psi. Provided centrally in the end plate 18 is a centralthreaded outlet opening 36. The outlet opening 36 is disposed about thelongitudinal axis of the filter assembly 10 and is within the circle ofsecond openings 34. In a presently preferred embodiment of theinvention, there are eight first inlet openings 30 and eight secondinlet openings 34 in the end plate 18. Other opening configurations thanround are feasible and the number of openings can be varied as will beapparent to persons skilled in the art, depending upon the applicationfor the filter assembly 10.

The combination valve 26 of the present invention includes a firstportion 28 that is annular and has a bend intermediate the radial extentof the first portion 28. The part of the first portion 28 that engagesthe second portion 32 extends generally horizontally and the free end isinclined outwardly and downwardly from the horizontal portion. Thesecond portion 32 includes an annular inwardly inclined part that isadapted to cooperate with the second inlet openings 34 and an upwardlyextending part 38 that cooperates with the horizontal part of the firstportion 28 to form a shoulder 40 that receives the lower inner end ofthe core 16 of the filter means. The part 38 is annular and engages theinterior of the lower end of the core 16 of the filter means whenassembled

The end plate 18 is suitably secured to the lid 20, for example, bywelding The recess 42 in the lid 20 is adapted to receive and retain thegasket 22 (FIG. 1). The lid 20 may be provided with projections thatslightly interfere with the recess 42, whereby in use, the gasket 22 isforced into the recess 42 and retained in place by the pressure from theprojections engaging and cooperating with the resilient gasket 22.

The resilient gasket 22 will be retained in the recess or groove 42during handling of the filter assembly 10 and the projections (notshown) define cooperative engaging means for holding the gasket inplace. Persons skilled in the art will understand that the gasket 22 canbe similarly retained in place in the recess 42 if the projections onthe lid 20 were eliminated and projections were provided on the outsideor inside surfaces of the gasket 22 for engaging with the walls of therecess 42. Such arrangement would function in an equivalent manner.

The end plate 18 is comprised of an outer generally transverse portion29, an inclined portion 31 and an inner transverse portion 33. Openings34 are disposed in a circle in the generally horizontal or transverseportion 33 of the end plate 18 and each has an axis that is generallyparallel to the central longitudinal axis of the filter assembly 10.Openings 30 are disposed in a circle generally concentric to the circlefor the openings 34 and spaced outwardly therefrom. The openings 30 arein the angled outward portion 31 of the end plate 18 and the axis ofeach of the openings 30 is inclined with respect to the centrallongitudinal axis of the filter assembly 10.

The filter means 15 may comprise a conventional pleated filter media 14composed, for example, of cellulose with some polyester. The core 16,which may be molded from an appropriate material, for example, a glassfilled plastic, such as, Nylon, is perforated so as to permit fluid flowthere through in use. Essentially, the core 16 comprises a cage formedby vertically disposed members 16 a suitably secured to horizontallydisposed members 16 b. The filter media 14 is formed from a sheet ofpleated material joined along the facing ends by a suitable adhesive toform an annular sleeve on the cage 16.

At the top and bottom are disposed end caps 50 and 52, respectively. Theend caps 50 and 52 may be fabricated from a suitable composite material,for example a cellulose/polyester composite. Preferably, the end caps 50and 52 are bonded to the filter media 14, for example, by ultrasonicwelding, to form a seal between the ends of the filter media and the endcaps to prevent fluid flow between these elements in use. Essentiallythe materials for the filter media 14, the core 16, and the end caps 50and 52 are compatible for ultrasonic welding to fuse the parts to oneanother. This process eliminates the need for adhesive and the ovencuring that was done in the past. The top end cap 50 is a generallyannular plate that has an opening in the center thereof for receivingand engaging the concave surface 13 of the housing 12 to help center thefilter means 15 in the housing 12. The elimination of the spring enablesa reduction in the overall height of the filter assembly 10, as well asa reduction in the interior void volume. By reducing the interior voidvolume, less oil is required to fill the system. The bottom end cap 52is a generally annular plate that has an opening in the center thereofand projections (not shown) extending from the periphery thereof. Asdisclosed in the prior co-pending application, there are threeprojections on the end cap 52. The projections are adapted to abut theinterior of the housing 12 to facilitate assembly of the filter meansinto the housing 12 and to properly position the lower portion of thefilter means 15 in the housing 12.

Resilient seals 56 and 58 are secured to the top end cap 50 and thelower end cap 58, respectively. The seals may be composed of felt orfelt-like material. The seal 56 may be affixed to the top end cap 50and/or the top of the core 16 and will seal between the end cap 50 andthe inner surface of the concave portion 13 of the housing 12. Theopening in the center of the annular filter media will be closed tofluid flow when the filter means 15 is assembled in the housing 12. Theresiliency of the seal 56 will apply a downward biasing force to thefilter means 15. The seal 58 may be affixed to the bottom end cap 52and/or the bottom of the core 16 to seal between the lower end of thefilter and the combination valve 26.

The assembly of the filter assembly 10 will now be described. The filtermeans 15 is assembled with the annular filter media 14 on the core 16and the end caps 50 and 52 secured in place. The end plate 18 and thelid 20 are secured together, for example, by welding, and the gasket 22is positioned and retained in the recess 42 of the lid. The filter means15 is positioned in the housing 12 abutting the closed end of thehousing, with the concave portion 13 engaged in the opening at the upperend of the filter means 15 help to properly center the top of the filtermeans in the housing 12. The seal 56 will preclude fluid flow betweenthe filter means and the housing 12. The combination valve 26 ispositioned in the core 16 with the part 38 engaging the inner surface ofthe core 16 to help seal fluid flow between the combination valve 26 andthe core 16 of the filter means. The seal 58 will preclude fluid flowbetween the filter means 15 and the contacted surface of the combinationvalve 26. The end plate 18 is inserted to close the open end of thehousing 12 and the outer rim of the lid 20 is rolled with the open endof the housing 12 to form a seal 80. Positioning of the end plate 18 inthe housing 12 partially compresses the seals 56,58, whereby, when theparts are assembled a spring force is applied to the top of the filtermeans 15 urging the filter means toward the end plate 18. The springforce will help to clamp the combination valve 26 between the filtermeans and the end plate 18 and to seal flow from between the filtermeans and the end plate 18. The core 16 will firmly engage the part 38of the combination valve 26 and will also engage and bear upon thegenerally horizontal region of the first portion 28 of the combinationvalve 26.

In operation, the filter assembly 10 is spun onto a stud on the engineblock which engages the threads in the central opening 36 in the endplate 18 and is secured in place. The gasket 22 will engage the engineblock and preclude fluid flow from between the engine block and thefilter assembly 10. When the engine is started, fluid, usually oil, willenter the filter assembly through the openings 30. Slight pressure willmove the first portion or check valve portion 28 of the combinationvalve 26 away from the openings 30 and oil will flow through openings30, the filter media 14 and be discharged through the cental outletopening 36 for return to the engine. When the engine is turned off, thefirst portion or check valve portion 28 of the combination valve 26 willclose the openings 30 and prevent return of oil in the filter assembly10 to the engine. As the filter media 14 clogs during normal operation,pressure will build within the housing 12 of the filter assembly 10 andupon attainment of a predetermined pressure, on the order of 8-10 psifor one present application, the second portion or bypass portion 32 ofthe combination valve 26 will open and permit oil to flow through theopenings 34 and back to the engine, thereby bypassing the filter media14. Stated somewhat differently, during periods of time when highdifferential pressure exists across the filter media, due to cold thickoil or high contaminant loading of the filter media, the oil will gothrough the inner circle of openings 34 and open the second portion 32of the combination valve 26 to permit oil to bypass the filter media 14and exit the filter assembly 10 through the outlet opening 36 for returnto the engine.

The concave portion 13 is not limited to the specific shape shown, butmay be configured shallower or deeper. It is important that the centralconcave portion or depression not extend above a plane at the top of thehousing 12 as seen in FIG. 1. Thus during manufacture, the housing canbe positioned open end facing upwardly on an assembly line.

The present invention materially reduces the number of parts needed fora line of filters. Presently standard automotive filter assemblies aregrouped into multiple filter diameters. A main line of filter assembliesheretofore consisted of multiple core diameters and multiple coreheights. With the present invention, filter sizes can be consolidatedand the complexity of internal components can be reduced significantly,for example to one core diameter and two core heights. Fabrication andassembly of the filter assemblies are simplified and can easily beautomated. The filter media, core and end caps are non-metallic and canbe easily recycled. The unique end cap design and orientation of theopenings therein is a facilitating factor in both construction andoperation of the filter assembly. The construction of the combinationcheck valve and bypass valve and the cooperation of the combinationcheck valve and bypass valve with the end plate contribute to easierassembly and enhanced performance. The respective circles of openings inthe end plate are fairly close to one another. The combination valve isconstructed so that it can be retained in place against the end plate bythe core 16 of the filter means by contact between the two circles ofopenings. This arrangement seals fluid flow through one circle ofopenings from the fluid flow through the other circle of openings.Tolerances need not be tight to obtain the sealing results desired.

Elimination of the spring employed in the design of the co-pendingapplication Ser. No. 10/715,682 by use of a concave portion in theclosed end of the housing reduces the overall height of the filterassembly. The concave portion 13 may be flatter or deeper in shapewithout adversely affecting the parameters of the present invention. Thecooperation between the concave portion of the housing 12 and theopening at the top of the filter means 15 helps to center the filtermeans 15 in the housing 12. The reduction of the overall height of thefilter assembly 10 reduces the interior void volume of the filterassembly 10 and thus less oil is required to fill the system. Further,the provision of the concave surface, as contrasted with a conventionalconvex surface, improves the manufacturing process by providing asurface that can be transferred down an assembly line in a threaded endup orientation easily and without the need for a fixturing device tohold the filter assembly upright.

While a presently preferred embodiment of the present invention has beenshown and described, it will be apparent to persons skilled in the artthat the invention may be otherwise embodied within the scope of thefollowing claims.

1. A filter assembly having a housing open at one end and closed at theother end, a concave portion being formed in the closed end of thehousing, an annular filter media/core assembly disposed in said housing,with the concave portion being disposed in the opening in the annularfilter media/core assembly, an end plate secured to the housing andclosing the open end thereof, the end plate having first inlet openingmeans, second inlet opening means and outlet opening means, acombination valve disposed between the annular filter media/coreassembly and the end plate for controlling fluid flow through the firstinlet opening means and the second inlet opening means, the combinationvalve including a first portion cooperating with the first inlet openingmeans and a second portion cooperating with the second inlet openingmeans, the second portion having more resistance to fluid flow than thefirst portion, whereby, in normal operation, the first portion willyield prior to the second portion and fluid flow will pass through thefirst inlet opening means, the annular filter media/core assembly andthen be discharged through said outlet opening means and when theannular filter media/core assembly begins to clog, pressure upstream ofthe first portion will build and upon attainment of a predeterminedpressure, the second portion will open the second inlet opening meansand fluid flow can pass through the second inlet opening means and outthe outlet opening means bypassing the annular filter media/coreassembly.
 2. A filter assembly as in claim 1 including resilient meansdisposed between the top of the annular filter media/core assembly andthe concave surface of the housing for sealing fluid flow between thetop of the annular filter media/core assembly and the concave portion ofthe housing and for biasing the annular filter media/core assemblytoward the end plate.
 3. A filter assembly as in claim 1 wherein thecombination valve comprises an annular member, with the first portionextending outwardly from a central portion and the second portionextending inwardly from the central portion, the second portion beingstiffer than the first portion; the annular filter media/core assemblyengaging the central portion of the combination valve between the firstportion and the second portion to retain the combination valve in place.4. A filter assembly as in claim 3 wherein the annular filter media/coreassembly includes a central core surrounded by filter media, and aresilient seal on the lower end of the central core engages the centralportion of the combination valve for sealing between the lower end ofthe central core and the combination valve.
 5. A filter assembly as inclaim 1 wherein the end plate has an inclined surface inclined withrespect to the longitudinal axis of the housing and a transverse surfacetransverse to the longitudinal axis of the housing, the first inletopening means being disposed in the inclined surface and the secondinlet opening means being disposed in the transverse surface.
 6. Afilter assembly as in claim 1 wherein the first inlet opening meanscomprises a plurality of openings.
 7. A filter assembly as in claim 1wherein the second inlet opening means comprises a plurality ofopenings.
 8. A filter assembly as in claim 1, wherein the annular filtermedia/core assembly comprises a core, a filter media surrounding thecore and end caps at the ends of the filter media, the filter media andend caps being fabricated from materials that can be bonded to fuse thecomponents to one another and preclude any significant fluid flow therebetween.
 9. A filter assembly as in claim 8, wherein the filter mediaand the end caps are ultrasonically welded to one another.
 10. A filterassembly as in claim 5 wherein the second portion has a surface engagingthe end plate and a surface engaging the central core.
 11. A filterassembly having a housing opening at one end and closed at the otherend, said closed end having a concave portion formed therein, an annularfilter media/core assembly disposed in said housing and having a centralopening in the upper end thereof, the concave portion of the housingbeing disposed in the central opening to help center the annular fittermedia/core assembly in the housing, an end plate secured to the housingand closing the end plate having first inlet openings, second inletopenings and an outlet opening the open end thereof, and a combinationvalve disposed between the annular filter media/core assembly and theend plate for controlling fluid flow through the first and second inletopenings, the combination valve including a first portion cooperatingwith the first inlet openings and a second portion cooperating with thesecond inlet openings, the second portion having more resistance tofluid flow than the first portion, whereby in operation, the firstportion will yield in response to minimum pressure and fluid flow willpass through the first inlet openings, the annular filter media/coreassembly and then be discharged through the outlet opening and when theannular filter media/core assembly begins to clog, pressure will beginto build and upon attainment of a higher predetermined pressure, thesecond portion will open the second inlet openings and fluid flow canpass through the second inlet openings and out the outlet opening,bypassing the annular filter media/core assembly.
 12. A filter assemblyas in claim 11 wherein the combination valve comprises an annularmember, with the first portion extending outwardly from a centralportion and the second portion extending inwardly from the centralportion, the second portion being stiffer than the first portion; theannular filter element engaging the central portion of the combinationvalve between the first portion and the second portion to retain thecombination valve in place.
 13. A filter assembly as in claim 12including resilient seal means disposed between the top of the annularfilter media/core assembly and the inside surface of the concave portionof the housing for sealing between the annular filter media/coreassembly and the inside surface of the concave portion of the housingand for biasing the annular filter media/core assembly toward the endplate to help retain the combination valve in place.
 14. A filterassembly as in claim 13 including resilient seal means disposed betweenthe bottom of the annular filter media/core assembly and the combinationvalve for sealing between the bottom of the annular filter media/coreassembly and for helping to retain the combination valve in place.
 15. Afilter assembly as in claim 11, wherein the closed end of the housinglies in a plane, with the concave portion extending inwardly from saidplane.
 16. A filter assembly having a housing open at one end and closedat the other end, said other end having a concave portion formedtherein, an annular filter media/core assembly disposed in said housingand having a central opening in the upper end thereof, the concaveportion of the housing being disposed in the central opening to helpcenter the annular fitter media/core assembly in the housing, an endplate secured to the housing and closing the open end, and a combinationvalve for controlling fluid flow through the filter assembly.
 17. Afilter assembly as in claim 16, including resilient seal means disposedbetween the top of the annular filter media/core assembly and the insidesurface of the concave portion of the housing for sealing between theannular filter media/core assembly and the inside surface of the concaveportion of the housing and for biasing the annular filter media/coreassembly toward the end plate to help retain the combination valve inplace.
 18. A filter assembly as in claim 16, wherein the closed end ofthe housing lies in a plane, with the concave portion extending inwardlyfrom said plane.